Excel Reader - Datatypes issue when run on loop

[PANCHAM_S_V]

So, the Excel reader reads data from an Excel file, checks the first 10,000 rows of data, and sets the data type of the columns accordingly.

Situation:
As you can see in the snapshot above, I am running the Excel reader in a loop with 9 files, and I want the data types of all columns in all 9 files to be set as strings without any manual intervention. These 9 files do not have the same columns; the columns are different in each file.

Please help me with this and reach out if you have a solution or an alternative.

[MartinDDDD]

Yesterday there was a topic about the exact same problem:
Solution: Set everything to string in transformation tab and then convert to desired data type (e.g. double) using appropriate nodes like String to Number.

Excel Reader - So Annoying -Transformation Tab

@MartinDDDD Hello Martin, Yes, I had considered that, but I decided to do it this way because some files were large, so I thought it would be better to process them one by one (even though, in the end, the Loop End concatenates them all together). About the issue It’s really difficult to simulate the error. I also don’t know why it happens. The most frustrating part is that I built this workflow for a friend, and she was running it but kept complaining about this error. I tested it on my …

[Felipereis50]

Vote for this too

Excel Reader / CSV Reader - Create a Force Type button

Create a button to force all columns to type (desired) or all to STRING. [image] Motive: every time why have, manually, to change the types to string. And sometimes, the node lost his configure and I have to change all again. Please, create a button to change the types all to string in one go.

[PANCHAM_S_V]

What I meant was, In excel files there are columns with datatype int,string,date etc but while I load them to KNIME I want them all to be in String.
How to do that when I am reading multiple excel files on loop

[PANCHAM_S_V]

How to create that button

[Felipereis50]

There’s no “button” to do that.

You’ll have to choose some strategies:

1. change manually (every time that lost configuration) (not a clever way )
2. Do not use the first row of excel reader has Header. Go to configuration os Excel Node and do this:
   
   
   
   Then, after the node completion, you can use the node “Row to column names”